"I'm not usually into amateur sleuthing but I was so angry after my own Brompton was stolen that when I saw a similar bike on eBay I got in touch with the seller and tracked him down," Mr A told BikeBiz.com.

This wasn't just a case of emailing for his address. First Mr A had to monitor the eBay seller to track the amount of Bromptons he was selling.

Contact was made, a request was put in for a specific and unusual Brompton and when the seller said he had located one, the police were informed and a meeting arranged. This took place at a McDonald's earlier today.

Mr A provided a frame number to the police. This was not the frame number on the bike being touted by the eBay seller so Mr A thought his hunch was wrong and his hours of research wasted. But, when Mr A gave the frame number to Brompton, it was quickly found this was another stolen Brompton.

This afternoon, police raided a house in East London and confiscated four Bromptons.

Mr A believes the eBay seller has sold 20+ Bromptons, at between £350 and £550 per bike. Some of these may be able to be reunited with their original owners.

If anybody has had a Brompton stolen in London in the last six months, they should contact Kensington and Chelsea police station on tel: 020 8246 9253.

PLUS:

Here's an Evening Standard story about a London police inspector found guilty selling stolen bikes on eBay. This story is not connected to the one above.